If you managed to purchase the limited edition version of Battlefield 3 you will be getting a the map pack for Karkand for free. Here is a list of what is coming according to the new trailer:

• 4 maps from Battlefield 2 made on the Frostbite Engine (Strike at Karkand, Gulf of Oman, Sharqi Peninsula and Wake Island)

• 3 new vehicles

• 10 new weapons

• Enhanced Destruction

• Extended Persistence

• Classic Conquest Assault